1. Field of the Invention
This invention relates to hand held icing dispensers, and more particularly to an icing dispenser that is self-pressurized independent of user squeezing.
2. Prior Art
It is well known to have hand held icing dispensers. Typically, a decorator tip is attached to an opening in a small collapsible bag filled with icing. An operator squeezes the bag to force icing from the bag through the decorator tip as the operator manipulates the tip about a surface to artistically decorate the surface with the icing.
Applying substantial hand pressure to squeeze out the icing while at the same time manipulating the tip with the wrist causes the operator""s hand and forearm to fatigue, resulting in loss of productive time while the operator rests. Of additional concern is that continual hand squeezing and wrist twisting while squeezing over a prolonged period of time greatly increases risk of an operator developing carpel-tunnel syndrome.
It is an object of this invention to provide an icing dispenser with an internal pressure system that delivers icing through a same decorator tip attached to a handle comfortable and familiar to an operator without the operator squeezing or otherwise exerting force to extrude the icing from the handle or a bag.
This object is achieved in an icing dispenser comprising a tip on a handle distal end and an expandable elastic reservoir on the handle proximal end. The elastic reservoir includes a neck that extends from an expandable reservoir bladder through a handle passageway to the tip. By design, the icing is retained within the bladder and the tip so the icing remains uncontaminated and the dispenser is easily cleaned. Cleaning then reduces to replacing the reservoir and washing the tip.
As the reservoir is loaded through a fill port under pressure, bladder expands under an elastic bias that tends to return the bladder to its unexpanded condition. This xe2x80x9cballooningxe2x80x9d reservoir is an advantage over piston-type pressurizers. Pressing icing forward through a tip by movement of a piston causes the icing to extrude unevenly from the tip. With radial pressure exerted from the bladder inwardly to the icing and uniformly around the entire bladder surface, this balloon-type pressurizer impresses constant pressure on the icing within the bladder without pressure xe2x80x9cdead spots,xe2x80x9d resulting in an even extrusion of icing from the tip. The pliable bladder is further preferred over other possible means of pressurizing its contents because of its mechanical simplicity.
A valve within the reservoir neck in the handle passageway modulates an amount of icing extruding through the tip and the passageway. The valve is typically a butterfly valve with wings rotating with a valve shaft extending through the neck out of the handle to a valve lever that controls the position of the butterfly wings in the neck. The valve seals the neck when ends of the butterfly wings close against the neck.
Although butterfly valves are commonplace, application to an icing dispenser requires a unique adaptation. Because icing characteristically comprises granular, undissolved sugar, a butterfly valve that would rotate butterfly wing ends to an orientation perpendicular to the passageway surface fails to seal the channel; sugar granules between the butterfly wing ends and the channel keep the butterfly wings from reaching its seal position. The butterfly valve of the present invention is therefore modified to include butterfly wing ends angled parallel to the passageway that urge the ends into the neck at a preferred angle, slightly resiliently deforming the neck around the ends to effect a seal. The angle is important because again the valve doesn""t seal both when the angle is too high and when the angle is too low as measured from normal to the handle passageway surface. When the angle is high the butterfly wings simply rotate through, pushing the pliable neck out of their way, or they stick to the pliable neck near the perpendicular orientation, making it difficult for the wings to move away from the neck. When the angle is too low, pressure of the icing prevents the butterfly wings from closing. It has been experimentally determined that the angle of the butterfly wings at the seal position must be between 45 degrees and 60 degrees, and ideally at 55 degrees.